So I ask the question... What sin are they talking about? According to the Bible, sin no longer exists and even more so, sin was only held against those whom were under the Old Covenant Law... which was the ancient Jews... the Gentiles or non-Jews weren't included in the Old Covenant, hence why the Jews were known as the "chosen people"!
But first things first...
Daniel prophesied that the Messiah (Jesus) would put an end to sin in Daniel 9:24
"Seventy 'sevens' are decreed for your people and your holy city to finish transgression, to put an end to sin, to atone for wickedness, to bring in everlasting righteousness, to seal up vision and prophecy and to anoint the most holy.
And Hebrews 9:26 confirms that this prophecy came true!
Then Christ would have had to suffer many times since the creation of the world. But now he has appeared once for ALL at the end of the ages to do away with sin by the sacrifice of himself.
The Law was the ministry of spiritual death (2 Corinthians 3:7)... one had to be under the Law in order to be "dead"... no one living today or for the Last 2,000 years has ever been under the Law, for the Law ended when the Old Covenant world / age ended. Gentiles / non-Jews were never under the Law / ministry of death to begin with!
YES, faith is important, for it enables us to experience the Kingdom / presence of God within us, but if people are still dead in their sins as Christianity tells us (sins that God supposedly has not counted against anyone for the last 2,000 years according to 2 Corinthians 5:19), then the Bible is worthless and Christ failed in His mission.
Not to mention... God is the one who created us with our human "sinful" nature... it would be incredibly unjust for God to create mankind with not only the ability to sin, but also the propensity to do so on a regular basis, if He was going to throw an eternal temper tantrum for people acting out how we were created. LOL
imo, the Bible and the very nature of God that I have experienced, both show me that God created humanity to be just as we are... as tools to teach us and grow us up to where we all will eventually be.
For Christians who think their faith is what God looks at in the bigger picture and everyone else is scum... well, the Jews thought that way too when Jesus welcomed the Gentiles to know the Father... and boy oh boy, did that piss them off, just as it ticks off Christians to think that unbelievers are just as right with God as Christians are!
If I may suggest, really get to know God, ask HIM a ton of questions... do not believe ANYTHING a preacher, pastor or other so called experts within Christianity tell you without asking God His opinion on the matter, no matter how much it seems to make sense!
Don't even believe me... the Lord is our teacher... ask HIM if these things be true and to make them real to you if they are!